U.S. patent application number 16/161678 was filed with the patent office on 2019-02-14 for microstructure separation filters.
The applicant listed for this patent is Imagine TF, LLC. Invention is credited to Brian Edward Richardson.
Application Number | 20190046897 16/161678 |
Document ID | / |
Family ID | 65274565 |
Filed Date | 2019-02-14 |
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United States Patent
Application |
20190046897 |
Kind Code |
A1 |
Richardson; Brian Edward |
February 14, 2019 |
Microstructure Separation Filters
Abstract
Microstructure separation filters are provided herein, as well
as chromatography and other separation devices. An exemplary filter
device includes a microstructure filter has a plurality of layers
of alternating sacrificial and/or structural material which have
been etched to create inlet channels and outlet channels. Adjacent
ones of the inlet channels and the outlet channels are spaced apart
from one another by cross channels that filter a fluid from the
inlet channels to the outlet channels. The cross channels include
filter features formed by etching away of a portion of the layers.
The device also includes a housing configured to receive the
microstructure filter.
Inventors: |
Richardson; Brian Edward;
(Los Gatos, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Imagine TF, LLC |
Los Gatos |
CA |
US |
|
|
Family ID: |
65274565 |
Appl. No.: |
16/161678 |
Filed: |
October 16, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14846154 |
Sep 4, 2015 |
10124275 |
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16161678 |
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62179582 |
May 11, 2015 |
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62176125 |
Feb 9, 2015 |
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62123717 |
Nov 25, 2014 |
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62070778 |
Sep 5, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 63/088 20130101;
B01L 2300/0816 20130101; B01D 15/125 20130101; G01N 30/603
20130101; B01D 69/02 20130101; G01N 30/6069 20130101; B01L 2400/086
20130101; B01L 2300/0681 20130101; B01D 63/082 20130101; B01L
2300/0809 20130101; B01L 3/502753 20130101; B01D 67/0062 20130101;
B01L 9/527 20130101; B01L 3/502707 20130101; B01L 2300/0803
20130101; B01D 15/22 20130101; B01D 2325/028 20130101; B01D 2325/08
20130101; G01N 30/6095 20130101 |
International
Class: |
B01D 15/22 20060101
B01D015/22; B01D 67/00 20060101 B01D067/00; B01D 69/02 20060101
B01D069/02; B01L 3/00 20060101 B01L003/00; B01L 9/00 20060101
B01L009/00 |
Claims
1-20. (canceled)
21. A filter device, comprising: a microstructure filter comprising
a plurality of layers of sacrificial material and an outer layer of
structural material, the layers being etched to create inlet
channels and outlet channels, wherein adjacent ones of the inlet
channels and the outlet channels are spaced apart from one another
by cross channels that filter a fluid flowing from the inlet
channels to the outlet channels, the cross channels comprising
filter features formed by etching away a portion of the sacrificial
layers; wherein the plurality of layers of sacrificial material
comprise: a base material; a first layer of sections of sacrificial
material, the sections being spaced apart from one another
equidistantly, the first layer being disposed on the base material;
a second layer of sections of sacrificial material deposited on the
first layer, the second layer comprising pairs of sections of
sacrificial material offset from the sections of the first layer so
as to cover spaces between the sections of the first layer; a third
layer of sections of sacrificial material deposited on the second
layer, the second layer comprising triplets of sections of
sacrificial offset from the sections of the second layer; a fourth
layer of sections of sacrificial material deposited on the third
layer, wherein sections are contiguous and extend across half of
the microstructure filter length; and the outer layer of structural
material being disposed on the fourth layer of sections of
sacrificial material; and a housing configured to receive the
microstructure filter, the housing being configured to connect to a
chromatograph device.
22. The filter device according to claim 21, wherein spaces are
etched into the microstructure filter to create openings.
23. The filter device according to claim 21, wherein the cross
channels comprise microstructure filter features formed by etching
away a portion of the sacrificial layers, the microstructure filter
features comprising nanostructures that increase a surface area of
the filter features to attract particles present in the fluid as
the fluid passes through the filter features from the inlet
channels to the outlet channels.
24. The filter device according to claim 21, wherein the filter
features comprise openings that are sized to capture a selected
size of particles present in the fluid.
25. The filter device according to claim 21, wherein the
microstructure filter comprises a plurality of spacer areas that
provide structural support between adjacent ones of the plurality
of layers of structural material, wherein the filter features are
disposed between adjacent ones of the plurality of spacer
areas.
26. The filter device according to claim 25, wherein adjacent ones
of the plurality of spacer areas are offset from one another to
stagger the filter features of adjacent layers of the plurality of
layers.
27. The filter device according to claim 21, wherein the
microstructure filter comprises an etched inlet section and an
etched outlet section.
28. The filter device according to claim 21, wherein the housing is
a tubular case that comprises an inner shell that receives the
chromatograph device.
29. The filter device according to claim 21, wherein at least a
portion of the filter features are provided with a nanoscale
surface treatment to increase surface area of the filter features
and thus an attractive force exerted by the filter features onto
particles in the fluid.
30. The filter device according to claim 21, wherein the housing
comprises a first connector that delivers fluid to the
microstructure filter, wherein the first connector is configured to
filter the fluid prior to entry into the microstructure filter.
31. The filter device according to claim 30, wherein the first
connection is a frit comprising an outer peripheral sidewall that
encircles a plurality of sections of passages.
32. The filter device according to claim 31, wherein the plurality
of sections of passages are disposed in a ringed configuration and
arranged such that passages of sections near a center of the frit
have smaller diameter passages than passages of sections near the
outer peripheral sidewall.
33. The filter device according to claim 31, wherein the plurality
of sections of passages each comprise passages with unique spacing
or diameters.
34. A filter device, comprising: a microstructure filter comprising
cross channels that filter a fluid flowing from inlet channels to
outlet channels, the cross channels comprising microstructure
filter features formed by etching away a portion of the sacrificial
layers; the microstructure filter features comprising
nanostructures that increase a surface area of the filter features
to attract particles present in the fluid as the fluid flows
through the filter.
35. The filter device according to claim 34, wherein spaces are
etched into the microstructure filter to create openings.
36. The filter device according to claim 34, wherein the
microstructure filter comprises a plurality of spacer areas that
provide structural support between adjacent ones of the plurality
of layers of structural material, wherein the filter features are
disposed between adjacent ones of the plurality of spacer
areas.
37. The filter device according to claim 36, wherein adjacent ones
of the plurality of spacer areas are offset from one another to
stagger the filter features of adjacent layers of the plurality of
layers.
38. The filter device according to claim 34, wherein the
microstructure filter comprises an etched inlet section and an
etched outlet section.
39. The filter device according to claim 34, wherein the housing is
a tubular case that comprises an inner shell that receives the
chromatograph device.
40. The filter device according to claim 34, wherein at least a
portion of the filter features are provided with a nanoscale
surface treatment to increase surface area of the filter features
and thus an attractive force exerted by the filter features onto
particles in the fluid.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of U.S.
Provisional Application Ser. No. 62/070,778, filed Sep. 5, 2014;
U.S. Provisional Application Ser. No. 62/123,717, filed Nov. 25,
2014; U.S. Provisional Application Ser. No. 62/176,125, filed on
Feb. 9, 2015; and U.S. Provisional Application Ser. No. 62/179,582,
filed May 11, 2015, all of which are hereby incorporated by
reference herein in their entireties, including all references
cited therein. This application is also related to U.S. patent
application Ser. No. 14/701,528, filed on May 1, 2015, which is
hereby incorporated by reference here in its entirety, including
all references cited therein.
FIELD OF THE PRESENT TECHNOLOGY
[0002] The present technology relates generally to separation
filters and chromatography, and more specifically, but not by
limitation, to microstructure substrates that comprise
micro-structured panels, complex flow orifices, and various types
of filtering systems configured from these substrates, such as
chromatography devices.
SUMMARY OF THE PRESENT TECHNOLOGY
[0003] According to some embodiments, the present technology may be
directed to a chromatography or other type of separation device,
comprising: (a) a microstructure filter comprising a plurality of
layers of structural material which are spaced apart to create
inlet channels and outlet channels, wherein adjacent ones of the
inlet channels and the outlet channels are spaced apart from one
another by cross channels that filter a fluid from the inlet
channels to the outlet channels, the cross channels comprising
filter features formed by removing a portion of the plurality of
layers of the structural material; and (b) a housing configured to
receive the microstructure filter, the housing being configured to
connect to a device to test the fluid.
[0004] The present technology may be directed to a filter device,
comprising: (a) a microstructure filter comprising a plurality of
layers of sacrificial material and an outer layer of structural
material, which have been etched to create inlet channels and
outlet channels, wherein adjacent ones of the inlet channels and
the outlet channels are spaced apart from one another by cross
channels that filter a fluid from the inlet channels to the outlet
channels, the cross channels comprising filter features formed by
etching away of a portion of the sacrificial layers, wherein the
plurality of layers of sacrificial material comprise: (i) a base
material; (ii) a first layer of sections of sacrificial material
are spaced apart from one another equidistantly, the first layer
disposed on the base material; (iii) a second layer deposited on
the first layer, the second layer comprising pairs of sections of
sacrificial offset from the sections of the first layer so as to
cover spaces between the sections of the first layer; (iv) a third
layer deposited on the second layer, the second layer comprising
triplets of sections of sacrificial offset from the sections of the
second layer; (v) a fourth layer deposited on the third layer,
wherein sections are contiguous and extend across half of the
microstructure filter length; and (vi) the outer layer of
structural material being disposed on the fourth layer; and (b) a
housing configured to receive the microstructure filter, the
housing being configured to connect to a chromatograph device to
test the fluid.
[0005] According to still other embodiments, the present technology
may be directed to a filter device, comprising: (a) a
microstructure filter comprising cross channels that filter a fluid
from inlet channels to outlet channels, the cross channels
comprising microstructure filter features formed by etching away of
a portion of the sacrificial layers, the microstructure filter
features comprising nanostructures that increase a surface area of
the filter features to attract particles present in the fluid as
the fluid passes through the filter features from the inlet
channels to the outlet channels; and (b) a housing configured to
receive the microstructure filter, the housing being configured to
connect to a chromatograph device to test the fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Certain embodiments of the present technology are
illustrated by the accompanying figures. It will be understood that
the figures are not necessarily to scale and that details not
necessary for an understanding of the technology or that render
other details difficult to perceive may be omitted. It will be
understood that the technology is not necessarily limited to the
particular embodiments illustrated herein.
[0007] FIG. 1 is an isometric view of the separation filter,
constructed in accordance with the present technology.
[0008] FIG. 2 is an isometric view of the filter panel of FIG.
1.
[0009] FIG. 3 is a front view of the filter panel shown in FIG.
2.
[0010] FIG. 4 is a close-up front view of the microstructure area
shown in FIG. 3.
[0011] FIG. 5 is an isometric view of the microstructure area shown
in FIG. 4.
[0012] FIG. 6 is a close-up view similar to what is shown in FIG. 4
that includes fluid flow lines.
[0013] FIG. 7 is a close-up view similar to what is shown in FIG. 4
that shows an alternate embodiment.
[0014] FIG. 8 is a close-up view similar to what is shown in FIG. 4
that shows an alternate embodiment.
[0015] FIG. 9 is a close-up view similar to what is shown in FIG. 4
that shows an alternate embodiment.
[0016] FIG. 10 is an isometric view of an alternate embodiment
shown in FIG. 9.
[0017] FIG. 11 is a different prospective of the isometric view
shown in FIG. 10.
[0018] FIG. 12 is a close-up view of FIG. 10.
[0019] FIG. 13 is a side view of the close-up shown in FIG. 12.
[0020] FIG. 14 shows the fabrication process for layered
microstructures.
[0021] FIG. 15 is a front view of an alternate embodiment of the
filter panel including a sensing area.
[0022] FIG. 16 is a front view of an alternate embodiment of the
filter panel that includes two microstructure areas and two sensing
areas.
[0023] FIG. 17 is an isometric view of an alternate embodiment of
the separation filter with multiple filter panels.
[0024] FIG. 18 is an isometric view of the through hole filter
panel section shown in FIG. 17.
[0025] FIG. 19 is an isometric view of an alternate filter panel as
shown in FIG. 18 with offset input and output.
[0026] FIG. 20 is a close-up view of an alternate embodiment of the
microstructure area of the filter panel shown in FIG. 4 that
includes fluid flow lines.
[0027] FIG. 21 is a close-up view of FIG. 20 with example
dimensions.
[0028] FIG. 22 is a close-up front view of an alternate embodiment
of the microstructure area shown in FIG. 4.
[0029] FIG. 23 is a perspective view of an example microstructure
filter panel.
[0030] FIG. 24 is a close up perspective view of the microstructure
filter panel of FIG. 23.
[0031] FIG. 25 is side perspective view of the microstructure
filter panel of FIGS. 23-24.
[0032] FIG. 26 is a perspective view of a plurality of
microstructure filter panels in stacked configuration.
[0033] FIG. 27 is a perspective view of an example microstructure
filter device for use in a chromatograph device.
[0034] FIG. 28 is a cross section view of the example
microstructure filter device of FIG. 27.
[0035] FIG. 29 is an end view of the microstructure filter device
of FIG. 28.
[0036] FIG. 30 is a perspective view of a microstructure
filter.
[0037] FIG. 31 is another perspective of the microstructure
filter.
[0038] FIGS. 32A and 32B collectively illustrate spacers and
openings of layers of the microstructure filter.
[0039] FIG. 33 illustrates nanoscale coatings applied to filter
features of a microstructure filter device.
[0040] FIG. 34 is another example microstructure filter device.
[0041] FIG. 35 is a close up view of a first end of the
microstructure filter device of FIG. 34.
[0042] FIG. 36 is an even closer view of the microstructure filter
of the microstructure filter device of FIG. 34.
[0043] FIG. 37 is yet a closer view of FIG. 36.
[0044] FIG. 38 is a perspective view of an example microstructure
filter device in a tubular configuration.
[0045] FIG. 39 illustrates the microstructure filter device of FIG.
38 in a cutaway view.
[0046] FIG. 40 is a perspective view of an example chromatograph
device.
[0047] FIG. 41 is an exploded view of the chromatograph device
illustrating a microstructure filter.
[0048] FIG. 42 is a view of a portion of the microstructure filter
of the device of FIG. 40.
[0049] FIG. 43 is a closer view of the microstructure filter of
FIG. 42.
[0050] FIGS. 44A and 44B illustrate additional perspective views of
the microstructure filter.
[0051] FIG. 45 is a perspective view of the microstructure filter
showing channels and bars.
[0052] FIG. 46 is a perspective view of the microstructure filter
showing spacer (structural) material.
[0053] FIG. 47 illustrates a cutaway section showing filter
features with nanoscale coatings.
[0054] FIG. 48 illustrates a top down view of layers of the
microstructure filter, showing offsetting of layers.
[0055] FIG. 49 illustrates a process of photoresist, deposition,
and etching to create a microstructure filter.
[0056] FIG. 50 illustrates a frit in combination with a
chromatograph connector.
[0057] FIGS. 51 and 52 collectively illustrate perspective views of
the frit, showing passages.
[0058] FIGS. 53 and 54 illustrate a front elevational view of an
example disk shaped microstructure filter device.
[0059] FIGS. 55-59 illustrate close up views of a microstructure
filter of the microstructure filter device of FIGS. 53-54.
[0060] FIG. 60 illustrates another detail section of the
microstructure filter of the microstructure filter device.
[0061] FIG. 61 illustrates a front elevational view of an example
disk shaped microstructure filter device with a layered
configuration.
[0062] FIG. 62 is a close up perspective view of the filter
features of the microstructure filter of the microstructure filter
device.
[0063] FIGS. 63-65 collective illustrate a process for creating
thin bars which form the filter features of the microstructure
filter.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0064] While this technology is susceptible of embodiment in many
different forms, there is shown in the drawings and will herein be
described in detail several specific embodiments with the
understanding that the present disclosure is to be considered as an
exemplification of the principles of the technology and is not
intended to limit the technology to the embodiments
illustrated.
[0065] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the present technology. As used herein, the singular forms "a",
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0066] It will be understood that like or analogous elements and/or
components, referred to herein, may be identified throughout the
drawings with like reference characters. It will be further
understood that several of the figures are merely schematic
representations of the present technology. As such, some of the
components may have been distorted from their actual scale for
pictorial clarity.
[0067] FIGS. 1-22 collectively illustrate separation filters with
microstructured panels. The microstructured panels are precisely
replicated on a film from tooling made with semiconductor
processing techniques. The separation panels can be covered with a
front cover or layered on top of one another to form enclosed
panels. The flow of liquids through the microstructured panels can
be affected by coating the surfaces of the panels with materials or
be constructed of materials that attract or repel particles or
molecules in the fluid. Alternately separation panels can be made
from semiconductor materials rather than being replicated from a
semiconductor master.
[0068] Referring first to FIG. 1, the separation filter is shown.
Fluids flow into the separation filter at the inlet tube. The
opening in the inlet tube extends through the front plate. Fluids
exiting the separation filter do so via the outlet tube. The
opening in the outlet tube also extends through the front plate.
The filter panel is sealed to the back side of the front plate. The
back side of the front panel would be generally a flat surface and
is not shown.
[0069] Referring to FIG. 2 the filter panel is shown without the
inlet tube, the outlet tube and the front cover. The inlet area is
coincident with the opening in the inlet tube. Similarly the outlet
area is coincident with the opening in the outlet tube. The inlet
area is a recessed pocket in the filter panel. Fluids flow from the
inlet area to the inlet expansion area. The inlet expansion area is
also a recessed pocket in the separation panel.
[0070] The cross section of the inlet expansion area is shown to
increase along the flow path. The amount of expansion, or
contraction would be a parameter that would be engineered for the
specific application of the separation filter. The depth of the
expansion is shown to be constant. This does not necessarily need
to be the case.
[0071] The inlet expansion area is connected to the microstructure
area. FIGS. 2, 3, 4 and 5 show the microstructure area at various
angles and level of detail. The microstructure area shares the same
depth as the inlet area and the inlet expansion area.
Microstructures are generally as tall as the depth of the
pocket.
[0072] As mentioned above the surface coating of the microstructure
panel or the material composition of the microstructure panel would
be of a type that interacts with compounds in the fluid. The
removal of chemicals and or particles from drinking water is one
applications of the disclosed separation filter. With this type of
filter it is desirable to retain chemicals or particles from the
fluid.
[0073] Another application of the separation panel is
chromatography. When used in chromatography different compounds are
usually separated from one another at different rates as fluid
flows through the separation filter.
[0074] It should be noted that the coating and or materials
deployed with the filter used for the specific separation task of
the filter is not part of this invention. One skilled in the art of
separation filters and the materials used for the specific
application could engineer a material for a specific fluid.
[0075] Referring to FIG. 5 the microstructures can be seen in a
magnified isometric view. The microstructures are generally a
diamond shaped cross section and extend from the pocketed surface
of the separation panel to the front face of the separation panel.
This particular embodiment has a constant cross section from the
base to the front face. The diamond microstructure geometry
generally results in a constant cross section of the fluid path
through the microstructure area.
[0076] Referring to FIG. 6, flow lines of a fluid flowing around
the microstructures is shown. These flow lines were generated with
a computational fluids dynamics analysis. It should be noted that
for most applications of the disclosed type filter the flow would
be laminar in type.
[0077] As fluid flows along the surface of the microstructures, a
boundary layer develops and grows in thickness. The fluid making
contact with the surface of the filter microstructures is
essentially stationary in relationship to the fluid flowing midway
between adjacent microstructures. The further the fluid is from the
surface of a microstructure the less likely a particle will be
attracted to the surface of the microstructure.
[0078] The midway point is where the fluid velocity is greatest.
This higher velocity fluid strikes the tips of the next column of
microstructures. The boundary layer that begins to form at the tip
of the next column of microstructures was previously the furthest
away from the surface of the 1.sup.st column of
microstructures.
[0079] Referring to FIG. 7 where an alternate embodiment of the
microstructure is shown. These microstructures are also arranged to
split the flow path as with the diamond design.
[0080] Referring to FIG. 8 where another alternate embodiment of
the microstructure is shown. The microstructures are tapered along
the flow path to compensate for the growth of the boundary
layers.
[0081] Referring to FIGS. 9, 10, 11, 12 and 13 where another
alternate embodiment of the microstructure is shown. These
microstructures differ from the previously disclosed
microstructures in that they do not have a constant cross section.
These microstructures have small spacers (in cross section) located
between larger thin planes of structural material. This embodiment
yields more surface area per section separation filter panel.
Panels of this type require a more complex manufacturing
process.
[0082] Referring to FIG. 14, the process to fabricate these
microstructures is described.
[0083] Referring to FIG. 15, additional "plumbing" has been added
to the separation panel. Channels to and from a sensing area are
shown. These additional features could be added to any of the
embodiments disclosed in this disclosure. The sensing area could be
used to measure the optical transmission or reflection of the fluid
as it exits the separation filter. This would be useful in the case
where the separation filter was used for chromatography.
[0084] Referring to FIG. 16, two different micro structured areas
and two sensing areas are combined in series along the flow path.
The first microstructure area might be coated with a different
material than the second area.
[0085] Referring to FIG. 17 where another alternate embodiment of a
separation filter is shown. The separation filter is configured
with many through hole filter panels sandwiched between the front
panel and the rear panel.
[0086] Referring to FIG. 18, the through hole filter panel is
shown. The inlet area of the through hole filter panels pass all
the way through the panel. This allows inlet and outlet fluids to
flow to all of the panels in the sandwich. The rear panel doesn't
have any holes.
[0087] Referring to FIG. 19, an alternate embodiment of the filter
panel with vertically offset inlet and outlet areas is shown. This
geometry yields flow paths that are more common in length than
disclosed in previous Figs.
[0088] Referring to FIG. 20, an alternate embodiment of the filter
panel is shown with slight vertical offsets in the vertical height
of the microstructures in the microstructure area. By slightly
offsetting the height of the microstructures the tip of the
microstructure cut through slightly different points in the flow
path. Without the offset the same cross sections of flow would
contact the surface of the microstructures over and over as the
flow progresses through them.
[0089] The flow lines are only shown for one elevation of the fluid
flow. Flow through a separation filter of this type would likely be
one with a low Reynolds number. Low Reynolds number flows result in
a laminar type boundary layer.
[0090] The first column cuts the flow stream at specific heights.
These heights can accurately be located when the microstructures
are fabricated directly from semiconductor type processes or if
they are replicated from a tool made from semiconductor processes.
The second column of microstructures cuts the flow field directly
in the center of the flow between the microstructures in the first
column.
[0091] The third column is off slightly vertically from the first
column. The fluid cut by the third column of microstructures is cut
slightly above the path cut by the first column of microstructures.
One would want to design this vertical offset while considering the
flow rate and attractive force between the particles or compound in
the fluid and the surface of the microstructure.
[0092] Successive columns of microstructures would be offset by the
same amount. With only a relatively small number of offset
microstructures one could insure that all areas of the flow path
pass within close proximity to the surface of a microstructure.
[0093] Example dimensions of the embodiment shown in FIG. 20 are
shown in FIG. 21. The design is shown with a 20 .mu.m space between
all of the microstructures. The third column of microstructures is
offset vertically upwards from the first column of microstructures
by 2 .mu.m. Fluid flowing 2 .mu.m above the center of the first
column of microstructures would eventually be cut in half by the
tip of a microstructure in the third column. Fluid flowing 4 .mu.m
above the center of the first column of microstructures would be
cut in half by the tip of s microstructure in the fifth column of
microstructures. To cut the fluid flow at every 2 .mu.m interval it
would require a total of 20 columns of microstructures. To cut the
fluid flow at every 1 .mu.m interval it would require twice as many
columns of microstructures. By varying the offset of pairs of
columns a system can be designed for efficient separation of
particles or compounds from a fluid. It should be noted that for a
column offset of 2 .mu.m a particle is no more than 1 .mu.m away
from a surface. It would be less than 1 .mu.m above or greater than
1 m below the surface of a microstructure. It should be further
noted that laminar flow of the fluid is required, if the flow was
to become turbulent the alignment of cuts would be disturbed.
[0094] It should be noted that these values are given to describe
the geometric advantages of 3D microstructure filter technology.
Those knowledgeable in fluid chemistry would want to engineer the
structure for the specific fluids, particles, microstructure
surface materials and flow rates.
[0095] The microstructures shown are ones consistent with ones made
with semiconductor processes or replicated from them. These
manufacturing techniques consistently produce features of a depth
of 10 times the width. Following this guideline the microstructures
could be 300 um deep. The entire cross section of the flow field
would then be 0.15 sq. mm. The length of the flow microstructures
would only need to be 2 mm long for a cut interval of 2 .mu.m. For
a 1 um cut interval the length would be 4 mm long. For a 4 mm
length the total volume of the microstructure volume would be only
0.6 cubic mm or 0.6 Cpl. Because of this tiny volume only a small
sample size is require. Further, because of the short path length,
the pressure to move fluid through the microstructures would be
relatively small. A further advantage is that all of the flow paths
are equal in length and cross section. This common path length
equates to consistent attraction of particles along the flow path.
If it is desirable to have a greater amount of fluid filters panels
could be laminated together as shown in FIG. 17.
[0096] Referring to FIG. 22 an alternate embodiment of the filter
panel is shown with microstructures that are truncated at the
trailing end. The truncation disrupts and generally mixes the flow
to mix the flow vertically. Mixed flow increases the likelihood
that all areas of the flow path will come in close proximity to the
surface of at least one microstructure. This embodiment is less
desirable that the previously described embodiment but would still
produce reasonable performance.
[0097] The present technology is directed to separation, and more
specifically, but not by way of limitation, to separation
mechanisms that comprise multiple microstructures made from or
coated with materials commonly used in separation. Some of these
materials are mentioned in the prior art section. These separation
microstructure panels are configured to maximize separation of the
compounds within the fluid. The separation filter may be used in
chromatography or reverse type chromatography.
[0098] FIG. 23 illustrates an example multilayer microstructure
filter panel 2300. The panel 2300 is illustrated in greater detail
in FIGS. 24 and 25. A close up view of a section of the panel 2300
is illustrated in FIG. 24 while a cross sectional view of a second
of the filter panel 2300 is illustrated in FIG. 25. The panel 2300
is comprised of a base material 2302, also referred to as a wafer.
A plurality of alternating structural and sacrificial layers (such
as structural layer 2304 and sacrificial layer 2306) are disposed
on the base material 2302. An example process for creating layered
structures is described in greater detail above. Also, additional
aspects of microstructure filter creation are found in applicant's
co-pending U.S. patent application Ser. No. X, filed on X, which is
hereby incorporated by reference here in its entirety, including
all references cited therein.
[0099] The alternating structural and sacrificial layers are etched
to create input and output channels, such as input channel 2308 and
output channel 2310. When portions of the sacrificial layers are
removed openings (e.g., holes, slits, cuts, slots, etc.) between
the input channel 2308 and output channel 2310 are created, which
allow for cross flow of fluid therebetween. The size of the
openings functions to remove particles from the fluid. In some
embodiments, rather than having openings, the sacrificial material
can be comprised of a porous material that filters the fluid.
[0100] In some embodiments, the panel 2300 comprises an outer layer
2312, which can comprise a photoresist layer. In one embodiment,
each of the structural layers is approximately 75 nanometers in
height, while each of the sacrificial layers is approximately 15
nanometers high. The outer layer 2312 can have a height of
approximately 1.5 microns. As mentioned before, the sacrificial
layers can be partially etched to create perforations or
openings.
[0101] Referring to FIG. 26, which illustrates a plurality of
multilayer microstructure filter panels stacked together. As
illustrated, fluid 2602 enters the input channels, such as input
channels 2604 and 2606, and passes through regions of cross
channels 2608 and 2610 and ultimately out of output channels such
as output channels 2612 and 2614.
[0102] To be sure, the multilayer microstructure filter panels and
stacks of multilayer microstructure filter panels can be utilized
to manufacture various filtering devices as well as chromatograph
devices, as will be described in greater detail below.
[0103] FIG. 27 illustrates another example filter device 2800
constructed from a plurality of multilayer microstructure filter
panels. The panel comprises a base housing 2802 that holds a
plurality of multilayer microstructure filter panels. The base
housing 2802 can be manufactured from a glass or silicon material,
as well as from other materials that would be known to one of
ordinary skill in the art with the present disclosure before them.
The device 2800 is configured to filter a fluid 2801 entering one
end of the device 2800 and exiting a terminal opposite end of the
device 2800 exiting a terminal opposite end of the device 2800.
[0104] The details of the plurality of multilayer microstructure
filter panels are illustrated in greater detail in FIGS. 27-32B.
FIG. 28 is a cross sectional view of the filter device 2800 of FIG.
27. The microstructure filter panel 2804 comprises an inlet 2803
and an outlet 2805. The inlet and outlet can be created through
etching or other similar processes.
[0105] FIG. 29 is an end view of the device 2800 illustrating a
multilayer microstructure filter panel 2804 nested within the base
housing 2802. FIG. 30 illustrates various spacer layers (structural
layers), such as structural layer 2806. A series of structural and
sacrificial layers comprise the microstructure filter panel 2804.
In one embodiment, the microstructure filter panel 2804 is etched
to expose a plurality of layered sections, such as layered section
2808.
[0106] FIG. 31 is a close up perspective view of a structure layer
section of the microstructure filter panel 2804. The structure
layer section illustrates various layers of structural layers, such
as structural layer 2810 and sacrificial layer 2812. A series of
spacers such as spacer 2810 can be comprised of sacrificial
material.
[0107] FIGS. 32A and 32B collectively illustrate additional
perspective views of the microstructure filter panel 2804 showing
the layering and openings created within the microstructure filter
panel 2804. The microstructure filter panel 2804 is illustrated
with spacers of sacrificial material 2812, structural layers 2806,
and sacrificial layer sections which are partially removed (or
entirely) to create openings 2814 through which fluid can flow.
[0108] In some embodiments, an effective surface area or fluidic
surface area of the microstructure filter panels, such as the cross
channels can be increased by creating nanoscale structures or other
texturing on the surfaces. For example, FIG. 33 is a close up view
of a cross channel section 3402 which is provided with a nanoscale
coating 3404. The nanoscale coating 3404 can be created through a
depositing process or by etching away of sacrificial material.
[0109] It will be understood that one of ordinary skill in the art
with the present disclosure before them would be capable of using
other conventional coating processes for creating three dimensional
features on the surfaces of the microstructure filter panels.
[0110] The three dimensional nature of the microstructure filter
panels, whether including nanoscale cladding or not, provides a
five-fold increase in particulate attraction forces compared with
filter devices of lower dimensions.
[0111] FIG. 34 illustrates another example filter device 3500. The
device 3500 also comprises a base housing 3502 that can be
manufactured from a glass or silicon material, as well as from
other materials that would be known to one of ordinary skill in the
art with the present disclosure before them. The base housing 3502
is configured with an inlet notch 3504 (a close view illustrated in
FIG. 35) and an outlet notch 3506. In some embodiments, a portion
of the inlet notch 3504 is angled relative to a reference line X.
In some embodiments, a portion of the outlet notch 3506 is also
angled relative to the reference line X. In one embodiment the
inlet notch 3504 angles upwardly as it extends from a first end of
the base housing 3502 and the outlet notch 3506 angles from a
narrow portion to a second end of the base housing 3502 that is
opposite the first end.
[0112] A plurality of multilayer microstructure filter panels is
combined to create a microstructure filter 3508 is disposed at an
angle .theta. relative to the reference line X. The filter panel
3508 extends between the inlet notch 3504 and the outlet notch
3506.
[0113] Fluid will enter the inlet notch 3504 and be dispersed into
the microstructure filter 3508. The fluid passes through the
microstructure filter panel 3508 into the outlet notch 3506. To be
sure, fluid can enter the microstructure filter 3508 along the
length of the inlet notch 3504 and exit the microstructure filter
3508 along the length of the outlet notch 3506.
[0114] FIG. 36 illustrates a close view of a portion of the
microstructure filter 3508. A plurality of layered sections, such
as layered section 3510 is illustrated, as well as a plurality of
structure/support sections 3512. Again, the layered sections can be
comprised of layers of structural and sacrificial materials.
[0115] FIG. 37 illustrates an even closer view of portion of the
microstructure filter 3508 presented in FIG. 36. The layered
section 3510 is comprised of a series of channels and sidewalls
3514 that filter the fluid as it passes through the microstructure
filter 3508. Each of the layers can comprise channels and sidewalls
of different thicknesses. For example, channels and sidewalls
disposed near the inlet notch 3504 can be sized to attract
particles larger than the particles attract by the channels and
sidewalls proximate the outlet notch 3506 (FIG. 34).
[0116] FIG. 38 is an example filtering device 3900 that is
constructed in accordance with the present technology. The
filtering device 3900 includes a tubular housing 3902 that
comprises an input port 3904 and an output port (not shown), which
is identical to the input port 3904 but disposed on an opposing end
of the filtering device 3900.
[0117] FIG. 39 illustrates that the example filter device 3500 of
FIGS. 34-37 is utilized in the filtering device 3900. That is, the
housing 3902 is configured to receive the example filter device
3500. The filter device 3500 can be used to filter any fluid for
any number of applications.
[0118] FIG. 40 illustrates an exemplary filter device 4100 in the
form of a testing column. The device 4100 comprises a housing 4102
having fittings 4104 and 4106. In some embodiments, the housing
4102 is separable into a first section 4108 and a second section
4110 as illustrated in FIG. 41. The device 4100 comprises a
microstructure filter 4112. The second section 4110 operates as a
cover that bounds the uppermost (or outermost) layer of the
microstructure filter 4112, ensuring that fluid transits through
the microstructure filter 4112. An input tube 4101 transmits fluid
from the fitting 4104 to the microstructure filter 4112.
[0119] FIG. 42 illustrates the microstructure filter 4112 in more
detail. The microstructure filter 4112 comprises an inlet 4114 and
outlet 4116. In some embodiments, the inlet and outlet are each
approximately one millimeter wide. The microstructure filter 4112
has layered sections 4120 and support sections 4122. The
microstructure filter 4112 is illustrated in FIG. 43 as having a
plurality of layered sections 4120A, 4120B, and 4120C that are
slightly offset from one another. For example, structural features
4124 of layered section 4120B are positioned slightly higher than
structural features 4126 of layered section 4120C. Cross channels
such as cross channels 4128 have a height that is approximately 50
micrometers and the width of the layered sections are approximately
32 micrometers. In some embodiments, a pitch between individual
cross channel features is ten micrometers.
[0120] FIGS. 44A and 44B are close up views of the microstructure
filter 4112.
[0121] FIG. 45 is a close up view of a layered section of the
microstructure filter 4112 illustrating channels, such as channels
4130 formed into layered sections (also referred to as "bars")
through etching.
[0122] In some embodiments, a spacer material 4132 is utilized to
maintain spacing of the layered sections as illustrated in FIG.
46.
[0123] FIG. 47 illustrates that the individual structural layers of
the layered sections (e.g., 4120A-C) can be coated or manufactured
with three dimensional coatings 4134. This again increases the
surface area of the layered sections, which improves the filtering
capabilities of the microstructure filter 4112. Again, one of
ordinary skill in the art could use various coating processes to
coat the individual structural layers to create artifacts that
result in the creation of three dimensional aspects on the
structural layers.
[0124] FIG. 48 is a top down view of the microstructure filter 4112
taken across section view A-A. The layered sections are shown as
comprising individual cross channel filter features, such as filter
features 4136. Again, filter features 4136 of adjacent layered
sections can be offset from one another, which allow the fluid to
be flowing close to a surface of a structural layer ensuring that
the fluid contacts at least one surface.
[0125] In some embodiments, the features of the structural layers
can be staggered or offset from one another by approximately one
nano-meter or any other distance per design requirements.
Offsetting of structural layers causes the fluid 4138 to divert
downwardly from filter features 4136 to adjacent filter features
4140. Also, offsetting of the layers and resulting features reduces
and/or eliminates the effect of accelerating of the fluid as would
commonly occur through a straight-line channel or path. The same
effect is produced in device of FIG. 21.
[0126] FIG. 49 illustrates the creation of a microstructure filter
which begins with a step S002 of photolithography and deposition of
a sacrificial layer. Sections of sacrificial material are spaced
apart from one another. Step S004 includes the photolithography and
deposition of another sacrificial layer that is offset from the
sacrificial layer in step S002. Pairs of sections of the second
sacrificial layer are placed on the first sections of the
sacrificial layer such that half of the sections of the first layer
are visible.
[0127] In step S006 photolithography and deposition of a third
sacrificial layer, which is illustrated as being offset from the
second sacrificial layer in step S004. Triplet sections of
sacrificial layers overlap the sections of the second and first
sacrificial layers.
[0128] In step S008 photolithography and deposition of a fourth
sacrificial layer is illustrated. The fourth layer is deposited on
the third layer in continuous sections, covering approximately half
of the microstructure filter. Next, in step S010 structural layers
are deposited over the sacrificial layers so as to create a
covering. The device is then etched in step S112 to create
openings, such as opening 5114.
[0129] In sum, with a series of photolithography, deposition, and
etch processes, staggered bars can be created. With four "digital"
layers 16 steps can be created and the layers can be staggered
incrementally at a distance of one nanometer or less.
[0130] FIG. 50 illustrates an exemplary filter device connector
5100 that comprises a frit 5102. The frit 5102 is placed into the
body of the connector in a path of fluid communication 5104. The
frit 5102 can retain particles as well as ensure that longitudinal
dispersion of these particles through the filter device is also
reduced. To be sure, the filter device connector 5100 can be
utilized as the fitting 4104 of FIG. 40.
[0131] The frit 5102 comprises a diameter D and a thickness as
illustrated.
[0132] FIGS. 51 and 52 collectively illustrate an example frit 5102
that comprises an outer peripheral sidewall 5106 that encircles a
plurality of sections of passages. For example, the frit 5102 can
include sections 5108A-E, which are each disposed in ringed
configurations. In some embodiments the sections are arranged into
hexagonal shapes of passages, although other shapes are likewise
contemplated for use.
[0133] In some embodiments, each section moving progressively
outward will be sized to capture a different size of particle. For
example, section 5108A has passages that are the smallest in
diameter, while section 5108E has passages that are largest in
diameter. Sections in between 5108A and 5108E have progressively
larger passages than the section which they encompass. In some
embodiments, each section can have a unique size of passages and
these sections need not be arranged in a linear manner with respect
to passage size.
[0134] In some embodiments, not only the diameter of the passages
can be varied but also the spacing of the passages. The density of
the passages can be tailored to design requirements for operation
of the device.
[0135] FIGS. 53-65 collectively illustrate further examples of
microstructure filters that can be utilized in the devices of the
present disclosure. In general, these microstructure filters can
comprise disks with microstructures (e.g., filter features) that
filter either particles or solutes from fluids. A top surface of
the disk would typically be mated to a flat surface to enclose the
flow channels on the micro structured disk. In some embodiments,
layers of disks can be stacked on top of one another. The disks can
be configured in parallel or in series configurations.
[0136] As with other microstructure filters, these disks can be
coated with different materials to filter different solutes in the
fluid. These coatings can include nanoscale structures. Disks with
different coatings can be configured in either in series or
parallel configurations as well. In some embodiments, the
structures can be coated with copper, zinc, carbon, resins and SiO2
are some materials, although many other coatings could be used.
[0137] FIG. 53 illustrates a microstructure filter 5400 in disk
shape. The filter 5400 comprises a plurality of inlet channels,
such as inlet channels 5402 that deliver fluid to a plurality of
horizontal channels, such as horizontal channels 5404. The filter
5400 also comprises outlet channels 5406 that collect fluid from
the horizontal channels. To be sure the inlet and outlet channels
can be switched relative to their configurations such that the
outlet channels become inlet channels and vice versa.
[0138] FIG. 54 illustrates two detail sections 5408 and 5410 that
will be described in greater detail herein. In FIGS. 55-59
illustrate filter features of the detail section 5408. For example,
in FIG. 55, both large and small flow channels are illustrated. An
inlet channel 5412 is illustrated, which feeds fluid to inlet
horizontal channels 5416 and outlet horizontal channels 5418. An
outlet channel 5420 collects filtered fluid from the inlet
horizontal channels 5416 and outlet horizontal channels 5418.
[0139] FIG. 56 illustrates horizontal channels with post filter
features 5422. Other filter features such as slits, notches, and
grooves of varying size and shape can be utilized as well.
[0140] FIG. 57 illustrates a top down view of the inlet horizontal
channels 5416 and outlet horizontal channels 5418.
[0141] FIG. 58 illustrates a top down view of the inlet horizontal
channels 5416 and outlet horizontal channels 5418 with post filter
features, and FIG. 59 is a close up view of a section of the view
of FIG. 58.
[0142] FIG. 60 illustrates detail section 5410 in more detail. The
detail section includes a vertical outlet channel 5424, horizontal
inlet channels 5416, and an outlet port 5418. In some embodiments,
the vertical outlet channel 5424, horizontal inlet channels 5416,
and support layers are coplanar with one another.
[0143] FIG. 61 illustrates another microstructure filter 6200 in
disk shape with a layered design. A more detailed view of filter
features 6202 of the filter 6200 is illustrated in FIG. 62. The
filter features comprise sidewalls instead of posts. In FIG. 64 a
more detailed view of the sidewalls is provided. In some
embodiments, the walls can be 0.1 nanometers tall and 0.05
nanometers wide.
[0144] FIGS. 63-65 illustrate a layer deposition process for
creating the sidewalls. In FIG. 63, thin bars 6402 are printed or
coated onto a support surface 6404. The material used in this
deposition process can be a sacrificial material. A second layer
6406 is deposited onto the bars 6402 and can be created from a
structural material.
[0145] Additional bars of structural and/or sacrificial material
can be applied to the bars 6402 as illustrated FIG. 64.
[0146] A view of a section of a completed filter disk is
illustrated in FIG. 65. To be sure, when sacrificial layers are
removed filter orifices 6602 (filter features) are created. Again,
the surface of these bars and surfaces can be coated as needed.
[0147] While various embodiments have been described above, it
should be understood that they have been presented by way of
example only, and not limitation. The descriptions are not intended
to limit the scope of the technology to the particular forms set
forth herein. Thus, the breadth and scope of a preferred embodiment
should not be limited by any of the above-described exemplary
embodiments. It should be understood that the above description is
illustrative and not restrictive. To the contrary, the present
descriptions are intended to cover such alternatives,
modifications, and equivalents as may be included within the spirit
and scope of the technology as defined by the appended claims and
otherwise appreciated by one of ordinary skill in the art. The
scope of the technology should, therefore, be determined not with
reference to the above description, but instead should be
determined with reference to the appended claims along with their
full scope of equivalents.
* * * * *